A best evidence topic in thoracic surgery was written according to a structured protocol. The question addressed was: what is the optimal level of suction on digital chest drainage devices following pulmonary lobectomy? Altogether 367 papers were found using the reported search, of which 4 randomized controlled trials using digital chest drainage devices represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. The new digital drainage systems enhance early mobilization as recommended in the enhanced recovery after surgery programme. There is, however, no consensus on the optimal level of suction to apply after pulmonary lobectomy. This is especially the case for digital drainage devices. Surgeon preference will likely continue to guide practice, until the evidence gives clear-cut recommendations. According to the current data, a low suction reduces total fluid drainage and perhaps air leak duration compared to higher suction levels in both video-assisted thoracoscopic surgery and open pulmonary lobectomies using digital drainage devices, although the evidence is not overwhelming.